An Early Look at a Few of the 

 Geneva Series Apple Rootstocks 

 In Massachusetts 



Wesley Autio, James Krupa, and Jon Clements 



Department of Plant & Soil Sciences, University of Massachusetts 



The Cornell-Geneva Rootstock Breeding Program 

 began in earnest in 1 968 by Dr. Jim Cummins. Its goal 

 was to produce rootstocks which resulted in a high 

 degree of precocity, high productivity, size control, 

 and resistance to pests. A particular focus of the 

 program was to breed fireblight resistance into 

 dwarfing rootstocks. Recent years have brought the 

 release of a number of rootstocks from this program, 

 but we have had very little experience with them in 

 Massachusetts. The first significant trial including 

 one of the recent releases was planted in 1 998, and the 

 next two were planted in 1999. This article will 

 provide early results from these three trials. Please 

 note that the first part of the rootstock name is "G" for 

 those Cornell-Geneva rootstocks that have been 

 commercially released. The names of those under trial 

 but not yet released begin with "CG." 



1998 NC-140 Apple Rootstock Trial 



As part of the 1998 NC-140 Apple Rootstock 

 Trial, a planting was established at the University of 

 Massachusetts Cold Spring Orchard Research & 

 Education Center, including Gala on M.9, M.9 EMLA, 

 and G.16. Trees were staked and maintained as 

 vertical axes. Trunk cross-sectional area, root 

 suckering, yield, and fruit size were assessed annually. 



After six growing seasons, trees on G.16 were 

 larger than those on M.9 or M.9 EMLA (Table 1). 

 Suckering has been low and comparable among the 

 three rootstocks. Trees on G.16 yielded more 

 cumulatively (1999-2003) than either strain of M.9, 

 but yield efficiencies were similar. Average fruit size 

 from 1999 through 2003 was smaller from trees on 

 G.16 than from either M.9 strain. 



28 



Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 



